I noticed a while ago while I was driving that a strange noise was coming from the undercarriage and this noise was amplified when I was driving next to a wall or barrier. The noise sounds like pennies in a jar while the wheels are moving or something to do with ball bearings. I took it into a GM dealer and they said that it was a leaking transfer case. Having no faith in dealership mechanics (trying to get the most money possible), So I just wanted to see if any other H3 owner had this issue before. It's a 2006 with around 90XXX miles on it.

 

While it may be something in the transfer case, a "leak" doesn't make any noise; the dealer needs to tell you what is actually making the noise in the transfer case.

Crawl underneath and see if you can see/feel anything loose. H3s are notorious for cracked exhaust system heat shields rattling; the shields are thin silver colored sheet metal, and crack or break with age, usually near mounting bolts. The result is a rattling noise at certain RPMs.

 

Thank you! I'll try that and see if I can figure out anything.

 

I had an issue somewhat as you describe, it ended up being the torque converter - the bearing was shot. I replaced the TC, all good now. When you're driving along that wall, quickly toss it into N and coast, does the sound go away?

 

big job!,,,did you pull the t case and tranny in one chunk?

 

It was actually very easy, with one guy doing extremely basic things to help me (passing me wrenches and soforth) it took an afternoon. If you look at my build thread I've actually got a pic of the change out. If you need additional pic I'll be happy to dig them out and post for you.

 

Kevwood, I did what you said and the noise was still there, it didn't go away when I shifted into N

 

Try putting your T case in Neutral.. Start up the engine still in N, then shift to D and let's see if there's the sound. I have the same issue, supposedly it's the worn-out T case chain. Just leave the P-brake because the truck will slide as the drive is disconnected. DO NOT SHIFT P WITH ENGINE RUNNING while the T case is in N position.